Industrial and Engineering Chemistry : analytical edition, Vol. 18, No. 1

A N A L Y T I C A L E D I T I O N 5

M EGAVAC PUMP

provides h igh vacuum for fractional distilla­

tions, for temperature and pressure measure­

ments, for circulating nitrogen through packed columns, and for other procedures in the analysis of com plex hydrocarbon mixtures.

T h e C en co M e g a v a c U n it com bines high vacuum, high speed, and dependable operation. Speed, 375 ml per second at 1 micron. Vacuum, 01. micron or better.

Proved for faithful, trouble-free service.

Catalog No. 92015A for 115-volts, 60 c y ... $155.

Technical personnel are invited to receive "C enco News C h ats" containing d e ­ scriptions of latest scientific apparatus. Ask for "C en co News C h a ts" No. 50.

CENTRAL SCIENTIFIC COMPANY

l a b o r a t o r y a p p a r a t u s S C IE N T IF IC IN S T R U M E N T S

NEW YORK TORONTO CHICAGO ^BOSTON SAN FRANCISCO

I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 18, No. 1

C H E M I C A L W O R K S

Mallinckrodt Street, St. Louis 7, Mo.

72 Gold Street, New York 8, N. Y.

C h ic a g o • P hilad elp hia • Los A n g eles * M ontreal

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A lw a y s S p e c ify R e a g e n ts I n M a n u f a c tu r e r ’s O r ig in a l P a c k a g e s I T C O S T S T O O M U C H ...

to u s e a n y t u t t k e t e s t r e ­ a g e n ts. It is w i s e e c o n o m y to s p e c i f y M a l l i n c k r o d t A n a l y t i c a l R e a g e n t s for tk e k i g k e s t u n i f o r m de- p e n d a t l e p u rity .

S e n d for t k e M a l l i n ­

c k r o d t A n a l y t i c a l R e ­

a g e n t c a t a l o g t o g e t k e r

w i t h a n y s p e c i f i c i n ­

f o r m a t i o n d e s i r e d o n

M a l l i n c k r o d t c k e m i c a l s

to f i t y o u r s p e c i a l i z e d

o p e ra tio n s .

A N A L Y T I C A L E D I T I O N

Now you can promise your customers vastly improved r e s is ta n c e is d e fin ite ly a s s u r e d w ith N o. 1337 autom otive refinishing coatings—an d d eliver on that Beckosol. Drying is phenom enally fast. Yet dura-

promise. This n ew pure RCI alkyd, modified with a

bility is all that can b e desired. Write for further pure phenol, giv es exactly those n ew results refin- facts and formulating suggestions direct to the Sales ishers h ave b een w aiting for! Superior water-spotting Department in Detroit.

R E I C H H O L D C H E M I C A L S , INC.

„ , G e n e ra l Offices a n d M ain Plant, Detroit 20, M ichigan

O th e r P lants:

Brooklyn, New York • Elizabeth, New Jersey • South S a n F ran cisco , C alifo rn ia • T uscaloosa, A la b a m a • Liverpool, E n g lan d • P aris, F ran c o • Sydney, A u stralia S Y N T H E T I C R E S I N S • C H E M I C A L C O L O R S • P H E N O L I C P L A S T I C S • I N D U S T R I A L C H E M I C A L S

HARSHAW SCIENTIFIC

D IV IS IO N OF THE H A R S H A W CHEMICAL CO.

CLEVELAND 6, OHIO

X? or hundreds of laboratory applications, Stainless Steel Beakers, available in six sizes from 1200 ml. to 8000 ml., offer a full m easure of convenience and a high level of perform ance, notw ithstanding th eir com paratively low cost.

%

B uilt especially for those requirem ents dem anding long use under severe service conditions, H arshaw Stainless Steel Beakers are m ade of 18-8 solid m etal, rust-proof, and cannot chip, scale or peel. T hey are tough, strong and highly resistant to denting, scratching, abrasions and binding.

Size A B

c

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Capacity, ml... 1200 2000 3300 4000 5800 8000

Diameter, mm... 125 140 175 180 200 225

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1 0 % Discount allowed when purchased in lots o f 12— one size o r assorted.

S T O C K S A L S O C A R R I E D I N C I N C I N N A T I • D E T R O I T • P H I L A D E L P H I A

A N A L Y T I C A L E D I T I O N 9

B. F. Goodrich Chemical Company

h a s a v a i l a b l e f o r s a l e t h e s e o r g a n i c c h e m i c a l s

: iTiSo“CÛ 1

O " -C 0 Î pi B Naphthtl p

P h e n y le n ®

W

— : * S L - . 5 S - * —

I Ä ”* ... !

t » y « * * ... : ... m O 0 0 > , O

S o - 1

c b

.

o

S O

c

- “« :

Distillation ra n g e >** . ... ...

(3.0 mm) • ... ...

Purity 9B% , • • • • • • • • • • • n r H n

... _ 0 c „ , o o o c " ' U i

• ... O -iO 0'--"’ : Oibemyl Ether ot Hjdroqoi- U o p r . p W f i P 'l 'J i f : . , »

A v ailab le in com m ercial q

’•

#

“ 1 « .

M p . 119

I , p 7 8 ° • Purity 8 5 / 0

'• ....

... .. ( C » J > C HO C - 6 )

0 * 0 ° « :

:

„ „ « . a . 1"

p H y d r o x y D i p h e n y l A m in e • Ä 9 8 %

SA ^{92% : •} ...

’ and Dimethyl cw 3 ^ ' ^

c s h

|

... : E S W t e - h * . , CH3- C -

s

7

• < _ > < _ > : A vai,aW. in com m ercial

* - * Ï q u an tities , 5 3 0

! N -N itro P o O iP » * ™ !-« « ; ! U f f £ S H - U '

: ‘ » T %

Purity 9 7 / 0 J . . « « • • • • • • • • • •

...

- 1

... iCH>-‘T N)c-sl

... O S O " » 0 :

^{M i x e d} A lip h atic T h if f lll

t c % - ° - s / U

I Disulfides . , r r- m 1

• l u t n P h e n y l e n e D i a m i n e • A v„ „ 0bie in c o m m e rç a c a H s - c c _ 5

D ip h e n y l p P n e n y i « <t . a „ o i

A v ailab le in co m m erce « q H - C - S

n I 4 4 ° A ‘—■

k

i 2 M P. 144°

Purity 9 2 %

F o r a d d itio n a l in f o rm a tio n p l e a s e w r ite B. F. G o o d ric h C h em ical C o m p a n y , D e p a r tm e n t C A -1 , R o se B u ild in g , C le v e la n d 1 5 , O h io .

B. F. Goodrich Chemical Companv

Two H D T -5610 High Temperature M uffle fur­

naces a t a major industrial research laboratory.

H E V I D ü T Y E L E C T R I C C O M P A N Y

T R A D E M A R K

LABORATORY FURNACES MULTIPLE UNIT ELECTRIC EXCLUSIVELY

I

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REG. U. S. PAT. O FF.

M I L W A U K E E , W I S C O N S I N

I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 18, No. 1

tools of progress. The tw o H D T -5610 High Tem perature A llo y 10 fu r­

naces shown are in d a ily operation in one of the country’s m ajor industrial research laboratories for studies of the effect of heat treatm ent on metals and alloys and fusibility of ceramic m a ­ terials. These Hevi Duty furnaces, w ith their uniform , exact, con­

trolled temperatures, are standard in most laboratories w here controlled heat to 2 3 5 0 ° F. is required. Bulletin H D -3 3 9 de­

tails their construction and use. Send for your copy — today.

January, 1946 A N A L Y T I C A L E D I T I O N

M E R C K & CO., Inc.

i/ t C a n iffíx c íu / iín if c(ç/ie m ii> /à

R A H W AY, N . J .

N ew Y ork, N . Y. • P hiladelphia, P a . • S t. Louis, M o. • E lk to n , Va. • C hicago, 111. • Los Angeles, Calif.

In C a n a d a : M erck & Co., Ltd., M ontreal • Toronto • V alleyñeld

P O T A S S I U M I O D I D E Merck Reagent

C r y s t a l s o r G r a n u l a r C o n f o r m s t o A .C .S . S p e c ific a tio n s

M a x i m u m I m p u r i t i e s I n s o l u b l e ...0 .0 0 5 % M o i s t u r e ... . . . . 0 . 2 0 % A lk a l i n i t y (a s K 2C 0 3) ... 0 .0 4 0 % C h lo rid e , B r o m id e (a s C l ) ...0 .0 1 % I o d a t e ( I O 3) ... 0 . 0 0 0 3 % N i t r o g e n c o m p d s . (a s N ) ...0 .0 0 2 % P h o s p h a t e (P O 4) ... 0 .0 0 5 % S u lf a t e (S O 4) ... 0 .0 0 5 % B a r i u m ( B a ) ... ... 0 .0 0 2 % C a l c iu m , M a g n e s iu m , a n d

N H 4O H p r e c i p ... 0 .0 0 5 % H e a v y m e t a l s (a s P b ) ...0 . 0 0 0 5 % I r o n ( F e ) ... 0 . 0 0 0 3 % S o d iu m ( N a ) . . . ... ; a b t._ 0 .0 3 %

K I M o l. w tJ 166.01 5 lb ., 1 lb ., VÍ lb ., a n d 1-o z. b o t t l e s

A M M O N I U M P E R S U L F A T E Merck Reagent

( C r y s ta ls )

A s s a y : M i n i m u m 9 5 % ( N H 4) 2S 20 8 C o n f o r m s t o A .C .S . S p e c ific a tio n s

M a x i m u m I m p u r i t i e s I n s o l u b l e ...0 . 0 2 0 % R e s id u e o n i g n i t i o n ...0 . 1 0 % C h l o r a t e a n d C h lo r id e (a s C l ) . . 0 .0 0 1 % H e a v y m e t a l s (a s o x i d e s ) 0 . 0 2 0 % M a n g a n e s e ( M n ) ... 0 . 0 0 0 1 %

( N H 4) 2S 20 8 M o l. w t. 2 2 8 .2 0 5 lb ., 1 lb ., Vi lb ., a n d 1 o z . b o t t l e s

P O T A S S I U M N I T R A T E Merck Reagent

(C r y s t a l s )

C o n fo rm s t o A .C .S . S p e c ific a tio n s M a x i m u m I m p u r i t i e s I n s o l u b l e ... ... 0 .0 0 5 % F r e e a c id (a s H N O 3) ... ____ 0 .0 0 7 % F r e e a l k a l i ... ... n o n e C h lo rid e ( C l ) ...•... ... 0 .0 0 1 % T o t a l c h lo rin e ( C l ) ... ... 0 .0 0 2 % I o d a t e ( I O 3) ... ... 0 . 0 0 0 5 % N i t r i t e ( N O j ) ... ... 0 .0 0 1 % P h o s p h a t e ( P O 4) ... 0 .0 0 0 5 % S u lf a t e ( S O ; ) ... ... 0 .0 0 3 % A m m o n ia ( N H 3) ... 0 .0 0 2 % C a lc iu m , M a g n e s iu m , a n d

N H 4O H p r e c i p ... ... 0 . 0 1 0 % H e a v y m e t a l s (a s P b ) ... 0 .0 0 0 5 % I r o n ( F e l ... ... 0 .0 0 0 3 % S o d iu m ( N a ) ... . a b t . 0 . 0 2 %

K N O 3 M o l. w t . 1 0 1 .1 0 5 lb ., 1 lb ., a n d V< lb . b o t t l e s

Some of the other Merck Reagents used b y Rubber Chem ists:

SODIUM HYDROXIDE REAGENT PELLETS SILVER NITRATE REAGENT SODIUM SULFIDE REAGENT BARIUM CHLORIDE REAGENT

T h e q u a l i t y o f M e r c k M i n e r a l A c i d s a n d A m m o n i a W a t e r i s i n k e e p i n g w i t h t h a t o f M e r c k R e a g e n t C h e m i c a l s .

Reagent Chemicals

U ntil th e Chemist Priestley suggested in 1770 that caoutchouc be used to erase pencil marks, th e elastic substance now known as rubber was regarded merely as a strange and useless article. Seventy years later Goodyear dis­

covered the process of vulcanization, and laid the foundation of the modern rubber industry.

Today, more than 30,000 different articles are made wholly or in part of rubber, and new uses are regularly developed. A brief trip through the M erck Plant discloses m any forms o f rubber employed in various operations visual evidence of the contributions made to the chemical industry by the rubber chemist.

Likewise, a visitor to the laboratory o f a progressive rubber chem ist will note the m any Reagent Chemicals bearing the Merck label—proof that Merck has kept pace by supplying th e chemicals essential for the develop­

m ent o f new uses for, and new forms of, a substance once regarded merely

as a curiosity.

12 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 18, No. 1

TODD SCIENTIFIC SPECIFICATIONS

PRECISE LABORATORY FRACTIONATION

An efficient and versatile laboratory fractionation column assembly w ith a new m ethod of adiabatic tem perature control for complete fractionation of m any types of organic liquid mixtures either a t atm ospheric pressure or under vacuum.

Covered by United States patent No. 2,387,479.

FEATURES:

1. F ra c tio n a tio n efficiency u p to 50 th e o re tic a l p lates.

PRESENT USERS:

A m erican C y a n a m id C o., B o und B ro o k , N . J.

A ndrew Jerg cn ’s C o., C in c in n ati, O hio A shland Oil & R efining C o., A sh lan d , K y . B ak e lite C o rp ., B o u n d B rook, N . J .

C arn eg ie I n s titu te of T ech n o lo g y , P itts b u rg h , P a . D ow C hem ical C o., F re e p o rt, T ex as

H o u d ry P ro cess C o rp ., M a rc u s H o o k , P a . Jo n es & L a u g h lin S teel C o rp ., P itts b u r g h , P a . M erck & C o., In c ., R ah w a y , N . J.

M o n sa n to C hem ical C o., T e x a s C ity , T exas N a tio n a l B u re au of S ta n d a rd s , W a sh in g to n , D . C.

N a tio n a l Oil P ro d u c ts C o., H arriso n , N . J . N ew Y o rk N a v y Y a rd , N . Y.

N orw ich P h a rm a c a l C o., N orw ich, N . Y.

Q u een ’s U n iv e rsity , O n ta rio , C an a d a R ay m o n d L a b o ra to ries, In c ., S t. P a u l, M in n . S h aw in ig an C h em icals L td ., Q uebec, C a n a d a S h a rp an d D ohm e, In c ., P h ila., P a . Shell Oil C o., In c ., W ood R iv er, 111.

S w a rth m o re College, S w a rth m o re, P a . T h io k o l C o rp ., T re n to n , N . J .

U . S. In d u s tria l C hem icals, In c ., N ew Y o rk , N . Y.

U n iv e rsity of C h a tta n o o g a , C h a tta n o o g a , T en n . U n iv e rsity of K an sa s, L aw rence, K an sas U n iv e rsity of V irginia, C h arlo tte sv ille, Va.

U n iv e rsity of W isconsin, M ad iso n , W is.

Velsicol C o rp ., C hicago, III.

Vick C hem ical C o., G reen sb o ro , N . C.

W esley an U n iv e rsity , M id d leto w n , C onn.

W y a n d o tte C hem icals C o rp ., W y a n d o tte , M ich.

2. F ra c tio n a tio n c h a rg e s fro m 2 cc. to 5 0 0 0 cc.

3. T e m p e ra tu re ra n g e fro m ro o m te m p e ra tu re to 4 0 0 °C . (7 5 2 ° F .).

4 . N e w p re c is io n d evice fo r a d ia b a tic te m p e ra tu re c o n tro l.

5. A tm o s p h e ric o r vacuum fra c tio n a tio n . 6 . T h re e in te rc h a n g e a b le fra c tio n a tin g co lu m n s.

7. Im p ro v e d s p ira l p a c k in g fo r sm all co lu m n . 8. R a p id fra c tio n a tio n w ith c o m p le te visability.

9. Easily o p e ra te d w ith a m in im u m o f e x p e rie n c e . 10. S pecial m a c h in e d s u p p o rts fo r a ss e m b lin g a p p a ra tu s.

11. P re c is io n c o n tr o l p a n e l fo r o p e ra tin g th e c o lu m n ’s " S ta g g e re d D u al H e a tin g U n it" a n d still p o t.

12. S pecial alu m in u m alloy still p o t w ith lo w te m p e ra tu re lag . 13. A ll m etal p a rts n o n -c o rro s iv e to n o rm a l la b o ra to ry a tm o s p h e re . 14. R a p id ly a ssem b led o r d is m a n tle d .

For additional experimental results, method o f operation, and details, see article, “Efficient and Versatile Laboratory Fractionation Column Assem bly,” by F. T odd, Ind. Eng.

Cbem., Anal. Ed., Volume 17, page 175, 1945.

FRAC TIO NA TIO N COLUMN ASSEMBLY includes:

(a) T h re e in te rc h a n g e a b le fra c tio n a tio n colum ns, 5, 12, a n d 25 m m . I.D . fo r 3 fo o t lo n g p a ck in g sec tio n s; all colum ns w ith T jo in ts a n d h o o k s fo r in s e rtin g co lum ns;

th e tw o la rg e r colum ns w ith s ta in le s s s te e l grid s fo r su p p o rtin g p a ck in g s. T h e 5 m m . I.D . precisio n fra c tio n a tio n co lu m n is su p p lied w ith th e im p ro v ed M o n el m e ta l s p ira l p a ck in g (p recisio n m a d e for hig h efficiency), (b) " S ta g g e re d D u a l H e a tin g U n it" (U . S. P a te n t N o. 2,387,479) fo r o p e ra tin g a sse m b ly u n d e r a d ia b a tic co n d itio n s from ro o m te m p e ra tu re u p to 4 0 0 °C . (7 5 2 °F .), in clu d in g tw o a tta c h e d 0 to 36 0 °C . th e rm o m e te rs ; (c) S till h e ad in te rc h a n g e a b le w ith th e th re e colum ns a n d w ith f ... "itill h e a ' * - - . . .

jo in ts ; (d ) S till h e a d th e rm o m e te r 0 to 3C0°C. w ith f j o in t a t 75 m m . im m ersio n m a rk ; (e) Im p ro v e d m icro- a n d m acro -co n tro l reflux re g u la to r w ith f jo in ts a n d w ith T g rooved s to p co c k ; (f) R eflux co n d en ser w ith T jo in t; (g) D istilla te c ondenser w ith s p h erica l jo in t, m e ta l c la m p , a n d d ro p c o u n te r b u lb ; (h) O u te r glass in su la to r j a c k e t 75 O .D . w ith s lo tte d sid e to receive s till h e a d ta k e-o ff a rm ; (i) C y lin d ric a l p o lish ed sta in le ss stee l a d d itio n a l in s u la to r ja c k e t to s u rro u n d re a r */j of e n tire co lu m n a sse m b ly ; (j) T w o sp ecially d esigned s tu r d y m e ta l su p p o rts for h o ld in g e n ­ tir e assem b ly in p o sitio n . All g lass p a rts P y rex b ra n d . O verall h eig h t of assem b ly 5'8*. C o m p lete as d e s c rib e d . ... $ 1 7 5 .0 0

Q u o ta tio n s on re q u e st fo r v a c u u m receiv er, v a rio u s sizes of s till p o ts, a n d reco m ­ m en d ed choice of 12 a n d 25 m m . I.D . co lu m n p a ck in g s n o t su p p lied .

P R E C IS IO N C O N T R O L P A N E L fo r o p e ra tin g th e c o lu m n ’s " S ta g g e re d D u al H e a tin g U n it” a n d s till p o t h e a te r. S p ecially desig n ed fo r e x tre m e ra n g e of te m ­ p e ra tu re co n tro l, se n s itiv ity fo r fine co n tro l, s ta b ility d u rin g co n tin u o u s o p e ra tio n , w ater-cooled fo r h e a v y d u ty , g en eral u tility , a n d n e atn ess of a p p e a ra n c e . P a n e l is finished in fine b la c k w rinkle en am el, ch ro m iu m s w itch p la te s, a n d p ro te c te d on th e b a ck w ith a m e ta l sh ield . Size 16* x 25*. F o r use on 110 v o lt a.c. or d .c .. .$ 6 5 .0 0

A L L -P U R P O S E L A B O R A T O R Y H E A T E R especially d esigned for h e a tin g th e co lu m n a sse m b ly ’s s till p o ts, w ith high th e rm a l efficiency a n d long life, a n d fo r p e r­

m ittin g th e fr a c tio n a tio n co lum ns to be b ro u g h t q u ic k ly to e q u ilib riu m co n d itio n s.

F a b ric a te d fro m sp ecial a lu m in u m allo y to re s ist co rrosion, for d u ra b ility , a n d w ith a m e ta llic sa tin -lik e finish fo r n e a t a p p e a ra n c e a n d m ax im u m h e a tin g efficiency.

Su p p lied w ith re m o v a b le h a n d le , fo u r re m o v a b le to p p la te s to fit a n y size flask from 10 to 5000 cc., sw itch , 7 f t. cord, a n d plu g . F o r use o n 110 v o lt a.c. or d.c. C om ­ p le te ... $ 2 5 .0 0

W rite fo r r e p r in t a n d T E C H N IC A L B U L L E T IN 100 fo r m o re d e ta ile d free in fo rm a tio n .

TODD SCIENTIFIC ^{g l a s s} a p p a r a t u s c o .

D e sig n e rs a n d m an u factu rers o f sp e c ia l scientific la b o ra to ry a p p a ra tu s.

DREXEL HILL, PA.

January, 1946 A N A L Y T I C A L E D I T I O N

ACCUTINT Test Papers are simple, rapid and accurate means of making hydrogen ion determinations. Merely p lace a drop of the solution b ein g ex­

am ined on a strip of the test paper, observe the color change w hich occurs, then make a com parison with the printed color standard on the vial. Each strip reacts to produce a distinctive color reaction at stated pH values within its range or indicates that an adjacent range must b e used for further determination.

W ide Range ACCUTINT Test Papers permit quick determination to establish the pH value within 0.5 unit in the range 0 to 14 pH w hile Fractional Range ACCUTINT Test Papers enable closer approximations to within 0.1 and 0.3 of 1 pH unit. W here a pH value cannot b e closely estimated, the use of w ide range papers is recomm ended to localize the pH value suni- ciently for quick, effective use of fractional range papers.

ACCUTINT Papers are as simple to use as Litmus Paper but are many times more informative: the 23 different ranges provide 144 separate color reactions. ACCUTINT Papers are furnished in pads of 20 strips each, live pads to a vial.

DISTRIBUTORS

E H S A R G E N T & C O . — 1 5 5 - 1 6 5 E. S u p e rio r Street, Chicago 1 1 , Hi.

M ic h ig a n D iv ., 1 9 5 9 E. Jefferson, D etroit 7 , M i c h .

Serves M id d le W est, G u lf States and M ountain States o f W e st G E N E R A L L A B O R A T O R Y S U P P L Y C O . — Paterson 3 , N . J. — S H erw o o d 2 -1 1 2 3

Serves the N e w Je rse y Territory T H E E M IL G R E IN E R C O . — 161 Sixth A v e n u e , N e w Y o rk, N . Y . P H IP P S A N D B IR D — Sixth and Byrd Streets, Richmond, V irg in ia

Serves Virginia, North Carolina, South Carolina

S T A N D A R D S C IE N T IF IC S U P P L Y C O R P . — 3 4 W . Fourth Street, N e w Y o rk , N . Y . W IL L C O R P . — Rochester, N e w Y ork

A L L other territory served b y :

A N A C H E M I A N E W Y O R K — 7 0 East 4 5 th Street, N e w Y o rk 1 7 , N . Y . M U rra y H ill 6 -0 7 5 3

W id e R a n g e A C C U T IN T T e s t P a p e r s

(65c p e r V ial)

A co v e rs r a n g e 0 t h r o u g h 5 p H B co v e rs r a n g e 1 t h r o u g h 12 p H C co v ers r a n g e 9 t h r o u g h 14 p H P a c k e d i n v ia l, 5 p a d s , 100 s t r i p s

(P le a se sp e c ify r a n g e s d e s ire d ) F r a c t io n a l R a n g e A C C U T IN T T e s t

P a p e r s (65c p e r V ial)

N o . F r a c t i o n a l R a n g e

1 0 ... 0 . 0 t h r o u g h 1 .2 2 0 ... 0 . 8 t h r o u g h 2 .4

3 0 . . ... 1 .3 t h r o u g h 3 .3 4 0 ... 1 .4 t h r o u g h 3 . 0

5 0 ... 1 .7 t h r o u g h 3 . 3 6 0 ... 2 . 7 t h r o u g h 4 . 7 7 0 ... 3 . 9 t h r o u g h 5 .4 8 0 ... 5 . 0 t h r o u g h 6 .6 9 0 ... 5 . 2 t h r o u g h 6 .9 1 0 0 ... 5 . 3 t h r o u g h 7 .0 1 1 0 . . . . , ... 6 .1 t h r o u g h 7 .4 1 2 0 ... 6 . 9 t h r o u g h 8 . 4 1 3 0 ... 7 . 2 t h r o u g h 8 . 8 1 4 0 ... 7 . 3 t h r o u g h 8 . 8 1 5 0 ... 8 . 4 t h r o u g h 9 .4 1 6 0 ... 8 . 9 t h r o u g h 1 0 .0 1 7 0 ... 9 .1 t h r o u g h 1 0 .4 1 8 0 . ... 1 0 .1 t h r o u g h 1 2 .0

1 9 0 ... 1 0 .7 t h r o u g h 1 4 .0 2 0 0 ...1 2 .4 t h r o u g h 1 4 .0

P a c k e d i n v i a l , 5 p a d s , 1 0 0 s t r i p s ( P l e a s e o r d e r b y R a n g e N u m b e r s ) M a s t e r A C C U T I N T C o l o r C h a r t , 2 1 x 1 0 K * . c o r r e l a t e s b y v a l u e a n d g r a p h i c a l l y a l l 1 4 4 p H v a l u e s , p e r c h a r t $ 3 .2 5 .

1 c o m p l e t e s e t o f A C C U T I N T P a p e r s , c o m p r i s i n g 2 3 v i a l s (3 w i d e r a n g e s a n d 2 0 f r a c t i o n a l r a n g e s ) a n d a n A C C U T I N T M a s t e r C h a r t , $ 1 8 .2 0 .

A N A C H EM IA ?o

C H E M I C A L

S P E C I A L T I E S

V

E.45 St., NEW YORK 17, N.Y.

Hydrogen Ion Concentrations ^{c a n n o w}

BE MEASURED W IT H IN 0.1 pH W IT H ACCUTINT TEST PAPERS

Simple

^—

N o I n s t r u m e n t R e q u i r e d Can Be Em ployed A n yw h ere C o lo r S c a le on Each V i a l

M aster Color Chart

Graphic Correlation

14 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 18, No. 1

F A B R 1 C A T E D F R O M V Y C O R 9 6 % S I L I C A G L A S S

LABORATORY GLASSW ARE

L A B O R A T O R Y G L A S S W A R E

• Introduced in 1939, distribution of Vycor brand Laboratory Glassware had barely started when World War II began and most of the ware was drafted. Now, however, “Vycor” is back in civies again and is being stocked by your laboratory supply dealer.

It is fabricated from Vycor brand 96% silica glass by a unique, patented method whereby most of the constituents other than silica are leached out.

It has a very low co-efiicient of expansion (approximately .0000008 per

°C, from 0° to 300° C), an extremely high softening point and exceptional chemical stability. Consequently, it is ideal for many types of important laboratory work. Reactions can be carried out at higher temperatures with greater speed and accuracy. In fact where use of fused silica was previously indicated, “Vycor” Glassware will ordinarily serve equally well at much lower cost.

A sufficient variety of shapes-beakers, crucibles, evaporating dishes, tubes, etc.—is now available to provide a fairly complete coverage of most upper temperature requirements. Consult your laboratory supply dealer.

Vycor is a registered trade-m ark an d indicates m anufacture by C o r n i n g G l a s s W o r k s , C o r n i n g , N e w Y o r k

T he Vi s i b l e G u a r a n t e e o f I n v i s i b l e Q u a l i t y

KIMBLE GLASS C O M P A N Y VIN E L A N D , N. J.

N E W Y O R K • C H I C A G O * P H I L A D E L P H I A • D E T R O I T • B O S T O N • I N D I A N A P O L I S • S A N F R A N C I S C O EXAX

^Tiir

L I N E

to m e e t a ll r e q u ir e m e n t s o f r e s e a r c h , a n a ly ­ s is a n d c o n t r o l. F o r e x a m p le , t h e f o llo w in g s e le c t io n s fr o m t h e K im b le l i s t o f m ic r o

a p p a r a t u s :

4 4 8 5 0 -ST P R EG L MICRO ABSORPTION TU BE

S IZ E E A C H

80 m m . $2.50 100 m m . $2.50

35012-ST PREGL PRECISION NITROMETER (AZOTOMETER) E ach $19.00

45159 MICRO CENTRIFUGE TUBE

1/s , 1, 2, 3, 5 m l. E ach $0.10

T h e 1/ä m l. an d 1 m l. sizes arc flan ged to fit h a n d c e n tr ifu g e s. O thers have reg­

u lar b ea d ed top . 46535-ST MICRO BU RETTE

S IZ E S U B D I V I S I O N S E A C H

5 m l. 0.02 S4.50

5 m l. 0.01 $5.50

10 m l. 0.02 $5.50 46465 MICRO WEIGHING TU BE

W ith g ro u n d g la ss cap. E ach $0.80

Consult leading Laboratory Supply Houses throughout the United States and Canada for Kimble Laboratory

Glassware to meet YOUR needs.

16 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 18, No. 1

A S C A R I T E

( R E G I S T E R E D T R A D E M A R K )

AGAIN AVAILABLE FOR SHIPMENT FROM OUR STOCK

ASCARITE, (Sodium Hydrate A sbestos Absorbent). Prepared in ac­

cordance with the formula of the late James B. Stetser for the rapid and quan­

titative absorption of CO

²

in the determination of carbon in iron and steel v and in universal use for this purpose in the iron and steel industry throughout

the w orld; also used in carbon-hydrogen determinations, particularly in quan­

titative organic microanalysis, and in the analysis of respiratory gases.

W hile originally designed for use in th e S tetser-N o rto n m odification of th e M idvale Ab- ^ sorption Bulb, it can be used w ith equal satisfaction in th e V anier, Flem ing, N esb itt, T u rn e r

and sim ilar bulbs an d is p articu larly recom m ended for use w ith th e M iller B ulb; 60 gram s of A scarite (the contents of a M idvale A bsorption B ulb) will absorb from 10 to 15 gram s of CO2. T herefore 500 gram s of A scarite provides for from 2,000 to 4,000 determ inations.

Because of th e difference in color betw een th e used a n d unused portions of th e absorbent, it is possible to determ ine exactly w hen a bulb should be discarded.

In m uch laboratory practice, A scarite is used w ithout an additional dry er b u t, w here use of th e la tte r seems advisable, we recom m end D eh y d rite as described below.

Bibliography

J . B. S tetser an d R . H . N orton, “ C om bustion T ra in for C arbon D eterm in atio n ,” T h e lr o n A g e , V o l.102, N o. 8 (Aug. 22, 191S).

T . H . H opper, “ C om bustion T ra in for th e D eterm in atio n of T o ta l C arbon in Soils,” In dustrial and Engineering Chemistry, A n a l Ed., Vol. 5, No. 2 (M ar. 15, 1933), p. 142.

W. R . K irner, “ M icrochem ical A nalysis of Solid Fuels,” ibid, Vol. 7, N o. 5 (Sept. 15,1935), p. 295.

R alp h 'O . Clark, and G ordon II. Stillson, “ M icrodeterm ination of C arbon a n d H ydrogen, U se of A braham czik A bsorp­

tion T ubes,” ibid, Vol. 12, N o. 8 (A ug. 15,1940), p . 494.

Alois Langer, “ Closed A bsorption T u b e for M icrodeterm ination of C arbon an d H ydrogen,” ibid, Vol. 17, N o. 4 (A p r., 1945), p. 266.

F ritz Pregl, "D ie Quantitative Organische M ikroanalyse,” 4th ed., (Berlin, 1935), p. 45; a n d 3rd English ed., (Philadelphia, 1937), p. 37.

1 lb. 500 gram 1 kilo

bottle b o ttle bottle

M esh 8 to 2 0 ... 4.10 M esh 20 to 3 0 ... 4 .1 0

D E H Y D R I

(R e g is te r e d T r a d e M a r k )

D EH Y D R ITE, (A nhydrous G ran u lar M agnesium P erch lo rate, S m ith). A agent for use as a w ater abso rb en t in carbon com bustions in steel analysis, in th e analysis of organic substances, an d in th e drying of gases including resp irato ry bon monoxide in air an d blood.

T h is anhydrous salt—as offered since 1937— has alm ost double th e m oisture absorbing ca­

p acity of th e trih y d ra te sa lt originally supplied u n d er our registered tra d e m ark, “ D E H Y ­ D R IT E . 1 I t possesses in ad d itio n th e following ad v an tag es:

F a c ility in charging, sin ce th e d ry in g a g e n t does n o t becom e s tic k y w hile m o m e n ta rily in -contact w ith a tm o sp h eric m o istu re.

C h an n els do n o t form in th e s a lt a n d d ecrease its efficiency.

T h e d e te rio ra tio n of th e re a g e n t is a cco m p an ied b y c o n tra c tio n in volum e, th u s re d u c in g th e te n d e n c y of d ry in g tu b e s to clog.

On a cco u n t of its p oro u s n a tu re , i t offers a lm o st n o re sista n c e to th e p assag e of gas.

C o tto n c an be used as plugs.

T h e sp e n t reag en t is easily rem oved from its co n tain er.

See G. F rederick Sm ith, “ M agnesium P erchlorate T rih y d ra te , Its U se as D rying A gent for Steel an d O rganic C om bustion A nalysis," In dustrial and Engineering Chemistry, Vol. 16 N o 1 (Jan., 1924), P -20.

P e r 250 gram cork stoppered b o tt le ... 1.92 P e r 500 gram cork stoppered b o ttle ... 3.5 2

A R TH U R H. T H O M A S C O M P A N Y

R E T A I L — W H O L E S A L E — E X P O R T

LA B O R A TO R Y APPARATUS A ND REAGENTS

W E S T W A S H I N G T O N S Q U A R E , P H I L A D E L P H I A 5 , P A ., U .S .A .

Cable Address “Balance” Philadelphia

4 .5 0 8 .5 0

4 .5 0 8 .5 0

590 GRAMS

/ D e h y d r i t e

INDUSTRIAL ^{a n d} ENGINEERING CHEMISTRY

P U B L I S H E D BY

Instrumentation in Analysis

I

^{n t h i s}

issue we inaugurate a new monthly feature, Instrumentation in Analysis,

prepared by Ralph H. Müller. Brief discussions of new instruments, methods, and apparatus of interest to analytical chemists, together with some discussion of their significance, field of application, and possible influence on the trend of future developments will appear over Dr. Müller’s signature. It is recognized that many devices and methods, which are not primarily concerned with chemistry, will ulti­

mately prove useful in analysis. This is particularly true in optical, electrical, elec­

tronic, and mechanical devices.

Dr. Müller is particularly well fitted by training and experience to cover the subject of Instrumentation in Analysis. He has been a member of the Radiation Laboratory of the Massachusetts Institute of Technology since 1942, and has done research in photochemistry, chemical physics, photoelectric photometry, electron­

ics, instrumental methods of analysis and control, design of industrial and scientific instruments, and radar. He is well known to our readers as the author of compre­

hensive articles on photoelectric methods in analytical chemistry, American ap­

paratus, instruments, and instrumentation, and instrumental methods of chemical analysis which appeared in 1939, 1940, and 1941. After receiving his Ph.D. from Columbia University and studying at Gottingen, he was on the staff of New York University from 1924 until he went to the M IT Radiation Laboratory to engage in highly secret research work for the war effort. In 1931 he received the silver medal of the American Medical Society for investigations on radium poisoning. Dr.

Müller has been a member of the Advisory Board of the

An a l y t i c a l Ed i t i o n

for several years and extremely active in its deliberations.

It is felt by your editors that the introduction of Dr. Müller’s column as a monthly feature is another step forward in a progressive and positive editorial program. The war stimulated greatly the development and use of instrumental methods of chemical analysis and unquestionably this trend will continue to grow in the future. There has been a long-felt need among analytical chemists for a timely, unbiased, and authoritative discussion and interpretation of new develop­

ments in the field of instrumentation.

Your editors and Dr. Müller will welcome suggestions and constructive criti­

cisms from our readers. We also will welcome suggestions on other subjects of special interest to analytical chemists that might be developed into regular monthly features with treatment similar to Dr. Müller’s presentation on- instrumentation.

We are here to serve the profession and the broad field of analytical chemistry.

l

Determination of Aromatics, Naphthenes, and Paraffins by Refractometric M ethods

R. M . G O O D I N G , N . G . A D A M S , a n d H . T. R A L L Petroleum E xperim ent Station, Bureau of M in e s , B artlesville, O k la .

M e th o d s are described (or determ ining aromatics, naphthenes, and paraffins in virgin naphthas and condensates bo ilin g b e lo w 3 2 0 ° F.

M o s t individual hydrocarbons catj be estimated to 2 4 3 ° F. Efficient fractionation is used to produce narrow-boiling-range fractions con­

taining relatively few individual hydrocarbons. Densities and re­

fractive indices for the mercury g line and the sodium D lin e , d e ter­

mined for each fraction at 2 0 ° C ., give specific dispersions and refractivity intercepts used for analysis of the samples. A rom atics are determ ined from specific dispersions and naphthenes, and paraf­

fins are determ ined b y use of m odified Kurtz and H ead in g to n refrac­

tiv ity in tercep t-d ensity charts. A rom atics can be determ ined from these charts with some loss in accuracy. D e v e lo p m e n t of the charts from experim ental and literature data is discussed and illustrated.

A nalyses of ten crud e-o il naphthas are given.

T

H E B ureau of Mines, since early in 1942, has been analyzing various virgin n ap h th a s and condensates to determ ine their possibilities as sources of aviation-gasoline base stocks, toluene, and o th er hydrocarbons. T hese analyses are based essentially upon fractional distillation of th e n a p h th a s or condensates, an d refractom etric exam ination of the distilled fractions. T h e final d a ta obtained from such analyses indicate th e q u an tities of aro­

matics, naphthenes, and paraffins boiling below 160° C. (320° F.) in th e sam ple. T he q u an tities of m ost individual hydrocarbons boiling below 117.22° C. (243° F .) can be determ ined. T h is re­

p ort describes a n d illustrates th e m ethod of analysis adopted, shows th e application of the m ethod to th e analyses of several crude oils, and indicates some uses of th e results.

A stu d y of th e m ethods used and proposed for th e determ ina­

tion of arom atics in sa tu ra te d hydrocarbon m ixtures indicated th a t arom atics in a crude oil could be conveniently an d accurately determ ined from th e specific dispersions of sm all narrow -boiling- range fractions obtained b y distillation of th e n a p h th a portion of th e crude oil. Among others, D ixm ier (3), W ard an d Fulw eiler (9), an d Grosse and W ackhcr (4) have used specific dispersion in hydrocarbon analysis. T he present m ethod in w hich th e specific dispersion is a m easure of th e q u a n tity of arom atic m aterial in a n ap h th a fraction, when th a t fraction contains only arom atics, naphthenes, and paraffins, is essentially a m odification of th a t of Grosse an d W ackher. Such a determ ination is possible because specific dispersions for naphthenes an d paraffins are nearly equal and co n stan t throughout the gasoline range, w hereas th e specific dispersions for arom atics, although n o t constant, are su b stan tially higher th a n th e values for naphthenes an d paraffins.

T he general equation for specific dispersion of a liquid is

S = j - n t X 10* (1 )

where S is specific dispersion, na is the refractive index for light of wave length a , n& is th e refractive index for light of wave length b, d is th e density, an d 104 is a facto r included for num erical con­

venience. All m easurem ents of physical properties are m ade a t one tem p eratu re, w hich for th is w ork is 20° C. A lthough disper­

sion m easurem ents of Grosse an d W ackher were m ade for th e F and C lines of hydrogen, the m easurem ents used in this w ork are for th e m ercury g line a n d the sodium D line. T h e la tte r two lines are used because convenient and reliable m ercury an d sodium lam ps are now com m ercially available and, since th e value of th e term n„ — nt, is g reater for these tw o lines th a n for th e F an d C lines of hydrogen, th e accuracy of the m ethod should be im proved.

A fu rth er m odification of th e m ethod of Grosse a n d W ackher is

in the use of very narrow -boiling-range fractions (usually less than 10 C.) ra th e r th a n fractions having a boiling range of a b o u t 25° C.

T h e determ ination of accurate values for th e specific dispersions of pure arom atics, an d of an average value for m ixtures of naphthenes a n d paraffins, as well as th e determ ination of arom atics in crude- 011 n ap h th as, is discussed by Thorne, M urphy, an d Ball (8).

T he determ ination of th e nap h th en e co n ten t of a sam ple is based on th e use of th e refractiv ity intercept, an em pirical prop­

erty originated by K u rtz and W ard (6). T h e presen t m ethod is a m odification of a n an aly tical procedure proposed b y K u rtz and H eadington (5) using th is property and applicable to m ixtures containing b o th sa tu ra te s and u nsaturates.

T h e refractiv ity in tercep t is defined by th e equation

R = rin — 0.5d (2)

where R is the refractiv ity intercept, n n is the refractive index for the sodium D line, a n d d is the density of th e liquid, all m easure­

m ents being m ade a t 20° C. As described by K u rtz an d W ard an d as used by K u rtz an d H eadington, R is a co n stan t for each h y ­ drocarbon ty p e o r homologous series. If a sam ple contains only arom atics, naphthenes, and paraffins, the use of the refractivity in te rc e p t as a n an aly tical tool depends upon th e relationship, usually shown graphically, betw een the refractiv ity intercepts a n d densities of th e sam ple a n d of the individual arom atics, naphthenes, an d paraffins th o u g h t to be present. F o u r m ajor m odifications have been m ade in th e m eth o d of K u rtz an d H ead­

ington: (1) only arom atics and sa tu ra te d hydrocarbons are con­

sidered in th e schem e of analysis; (2) th e graphical analysis ch a rts cover an average boiling range of 10° C. in stead of 30° C.;

(3) very' narrow -boiling-range fractions are analyzed; (4) indi­

vidual values for refractiv ity intercepts are used for all compounds instead of a single value for each type.

A fter th e aro m atic an d nap h th en e contents of a fraction con­

taining only arom atics, naphthenes, and paraffins h ave been de­

term ined, th e paraffin co n ten t of th e fraction is ob tain ed b y differ­

ence. A rom atics can be determ ined by th e use of refractivity in tercep t an d density, b u t it is felt th a t th e p resen t determ ination of arom atics from specific dispersions is m ore accurate. A com­

parison of resu lts b y th e two m ethods is given in T ab le I.

A N A L Y T I C A L A P P A R A T U S A N D P R O C ED U R E

T h e accuracy of th e analytical m ethod described below depends in p a r t on th e a p p a ra tu s, a n d its q u a lity m u st be such t h a t data of th e requisite accuracy an d precision are obtained. T h e equip­

m en t described in th e following p aragraphs h as been found satis­

factory for th is work.

Tw o types of colum ns are used for th e fractional distillation of sam ples. In one assembly' th e colum n proper is a glass tu b e 21 m m . in inside d iam eter packed w ith single-turn w ire helices 2.4 mm . (V32 inch) in diam eter. T he packed section is 244 cm. in length, an d is insulated w ith asbestos listing a n d m agnesia. A

system of electrical h eate rs is incorporated in th e insulation, so th a t th e tem p eratu re of th e insulation can be m ain tain ed a t or slightly below th e tem p eratu re of th e v ap o r and liquid w ithin the column. T hese tem p eratu res are m easured by 5 pairs of iron- co n stan tan therm ocouples spaced along th e length of th e column.

T he glass still p o t is perm anently' sealed to the colum n proper and h as a capacity' of 4.5 liters. A to ta l condenser a t th e to p of. the colum n provides reflux an d liquid overhead p roduct. T h e col­

um n w as tested in th e usual m an n er using methydcy'clohexane and isooctane, an d has a n efficiency a t to ta l reflux equ iv alen t to 88 theoretical plates.

T h e o th er distillation u n it is a commercially' available vacuum- jacketed glass colum n haying 122 cm. of p a te n te d w ire packing.

2

Table I. Comparison of D eterm ination o f A ro m a tics b y Specific Dispersion and b y R efractivity In te rc e p t-D e n s ity M e th o d s V olum e P e r C e n t of A ro m atics in N a p h th a o r C o n d én sate

C artlm n e C h ap e ! Ilili_______ C onroe_____________ E a s t T exas___ H ull-S ilk-S ikes (S traw n)

Specific d isp er­

R efra c ­ tiv ity

i n te r ­ D iffer­ Specific d is p e r­

R efrac­

tiv ity

in te r­ D iffer­ Specific d isp er­

R efrac­

tiv ity

in te r­ D iffer­ Specific d isp er­

R efra c ­ tiv ity

in te r­ D iffer­ Specific d isp er­

R efrac­

t i v ity in te r­ D iffer­

A ro m atic sion c e p t ence sion c e p t ence sion c e p t ence sion c e p t ence sion c e p t ence

B enzene 2 .0 5 1 .7 8 0 .2 7 0 .5 4 0 .4 0 0 14 1 . 9 Í 1 .9 0 0 .0 4 0 .2 4 0 .1 6 0 .0 8 0 .1 6 0 .1 5 0.0 1

T oluene 0 .8 8 0 .8 2 - 0 .0 6 0 .5 2 0 .4 4 0 .0 8 9 .7 2 9 .3 7 0 .3 5 1.1 4 0 .8 7 0 .2 7 0 .8 1 0 .5 5 0 .2 6

E th y lb en z e n e 0 .1 6 0 .1 2 0 .0 4 0 .3 2 0 .2 3 0 .0 9 0 .3 7 0 .3 4 0 .0 3 0 .3 8 0 .2 5 0 .1 3 0 .3 1 0 .2 0 0 .1 1

rn-X ylene )

p -X y le n e J 0 .5 4 0 .5 0 0 .0 4 0 .4 3 0 .3 3 0 .1 0 3 .5 2 3 .4 2 0 .1 0 1 .3 3 1 .1 5 0 .1 8 0 .8 1 0 .5 5 0 .2 6

o-X ylene 0 .2 4 0 .1 9 0 .0 5 0 .1 5 0 .1 2 0 .0 3 1.5 5 1.5 0 0 .0 5 0 .6 4 0 .5 4 0 .1 0 0 .2 4 0 .1 3 0 .1 1

Isopropylbenzene 0 .0 8 0 .0 4 0 .0 4 0 .0 9 0 .0 6 0 .0 3 0 .1 9 0 .1 2 0 .0 7 0 .2 2 0 .1 0 0 .1 2

n -P ro p y lb en zen e 0 .2 2 0 .2 1 0.0 1 0 .5 1 0 .1 8 0 .0 3 0 .5 2 0 .4 5 0 .0 7 0.4 1 0 .3 4 0 .0 7

B enzene 1 .0 3

Je n n in g s 0 .9 4 0 .0 9

K M A (S traw n )

0 .2 4 0 .2 4 0 .0 0 0 .1 3

M n u m e n t

0 .0 8 0 .0 5 1 .0 2

Old O cean

0 .9 2 0 .1 0 0 .1 6

P ly m o u th 0 .1 1 0 .0 5

T oluene 3 .5 1 3 .4 5 0 .0 6 1 .0 4 0 .9 0 0 .1 4 0 .4 8 0 .3 0 0 .1 8 2 .6 9 2 .4 9 0 .2 0 0 .7 2 0 .6 2 0 .1 0

E th y lb en z e n e 0 .4 8 0 .4 1 0 .0 7 0 .3 4 0 .3 0 0 .0 4 0 .4 4 0 .3 3 0 .1 1 0 .5 1 0 .4 3 0 .0 7 0 .3 5 0 .3 2 0 .0 3

m -X ylene )

p -X y le n e J 3 .4 8 3 .3 8 0 .1 0 1 .1 9 1.0 5 0 .1 4 0 .5 0 0 .3 1 0 .1 9 2 .7 9 2 .4 6 0 .3 3 0 .7 5 0 .5 8 0 .1 7

o -X ylene 1 .8 7 1 .8 6 0 .0 1 0 .5 2 0 .4 3 0 .0 9 0 .0 8 0 .0 3 0 .0 5 1 .6 0 1 .3 5 0 .2 5 0 .3 1 0 .2 5 0 .0 6

Iso p ro p y lb en zen e 0 .4 2 0 .3 5 0 .0 7 0 .1 7 0 .1 5 0 .0 2 0 .1 8 0 .1 1 0 .0 7 0 .1 9 0 .1 5 0 .0 4

n -P ro p y lb en zen e 0 .8 7 0 .7 4 0 .1 3 0 .5 5 0 .5 2 0 .0 3 0 .4 8 0 .4 1 0 .0 7 0 .3 2 0 .3 2 0 .0 0

B enzene 0 .0 0

S a x e t

0 .0 5 - 0 . 0 5 0 .5 9 Segno

0 .5 4 0 .0 5 4 .6 0

S lau g h ter

4 .1 2 0 .4 S 0 .1 0

W ade C ity

0 .0 8 0 .0 2 2 .2 9

W asson 1 .9 8 0 .3 1

T oluene 0 .0 0 0 .0 6 - 0 . 0 6 3 .2 2 3 .0 7 0 .1 5 4 .8 0 4 .5 0 0 .3 0 0 .7 9 0 .6 6 0 .1 3 4 .4 4 4 .1 6 0 .2 8

E th y lb en z e n e 0 .4 9 0 .4 0 0 .0 9 0 .4 2 0 .3 5 0 .0 7 1 .1 0 0 .8 3 0 .2 7 0 .5 4 0 .4 5 0 .0 9 0 .9 1 0 .7 6 0 .1 5

m -X ylene 1 p -X y len e J o-X ylene

0 .5 8 0 .4 4 0 .1 4 3 .0 7 2 .8 6 0 .2 1 2 .8 6 2 .7 8 0 .0 8 1.4 3 1 .2 4 0 .1 9 3 .1 3 2 .9 1 0 .2 2

0 .0 7 0 .0 6 0.0 1 1 .6 7 1 .5 4 0 .1 3 0 .7 8 0 .7 2 0 .0 6 0 .9 1 0 .7 5 0 .1 6 1 .1 9 1 .0 5 0 .1 4

Iso p ro p y lb en zen e 0 .1 6 0 .0 0 0 .1 6 0 .4 8 0 .4 1 0 .0 7 0 .3 4 0 .2 7 0 .0 7 0 .2 9 0 .2 1 0 .0 8 0 .4 7 0 .3 9 0 .0 8

n -P ro p y lb en zen e 0 .2 7 0 .2 6 0 .0 1 0 .8 8 0 .7 2 0 .1 6 0 .8 1 0 .7 4 0 .0 7 0 .7 4 0 .7 1 0 .0 3 0 .8 5 0 .7 9 0 .0 6

T he diam eter of th e w ire packing is 22 mm. T he still p o t is a 5- liter flask w ith a spherical ground-glass joint. T he vacuum jacket requires no auxiliary h eating w hen th e colum n is operating below 320° F . A to ta l condenser fits in to the top of th e column and provides reflux an d liquid overhead product. T he fractionating efficiency of th is colum n a t to ta l reflux is 50 theoretical plates a t th e vaporization ra te used in these distillations. In all columns the tem p eratu re of th e v ap o r a t th e top of the colum n is measured by m eans of iron -co n stan tan therm ocouples w ith a precision of 0.3° F. (0.17° C .). T h e peaks for p articular compounds in the plo t of volum e per cent ag ain st tem perature as m easured by the therm ocouples usually agree w ith th e literatu re values for boiling points of th e p a rtic u la r com pounds to 10 F.

R efractiv e index m easurem ents are m ade in a Bausch & Lomb precision oil refracto m eter using m onochrom atic light. L ight is provided by com m ercially available lam ps a t th e wave lengths of the m ercury g line (4358 A.) a n d th e sodium D line (5893 A.).

T h e precision of these m easurem ents is ±0.00010 u n it of refrac­

tive index for routine determ inations. Specific gravities are de term ined a t 20° C ./2 0 0 C. w ith a chainom atic W estphal balance using a 2-ml. glass plum m et. T h e precision of these m easure­

m ents is ± 0.0002 u n it of specific g rav ity . Specific gravities are converted to densities a t 20° C.

A m easured volum e of th e sam ple is introduced into th e still pot. _ T h e volum e of th is charge m ay be from 2 to 4 liters, b u t usu­

ally is betw een 3 an d 3.5 liters. T he colum n is preflooded to in­

crease sep aratin g efficiency, an d then allowed to operate a t the still-pot pressure m ain tain ed throughout th e distillation for 1 hour or longer. P ro d u c t w ithdraw al is begun a fte r th is stabilizing pe­

riod, an d is ad ju sted to give a take-off ra te of 1 m l. per m inute.

A reflux ratio of 20 to 1 is m aintained by an a p p ro p riate vaporiza­

tion rate th ro u g h o u t th e distillation. F ractions are collected every 8 or 9 m inutes, an d th e tem perature of th e vapor a t th e to p of th e column is recorded a t th is time. This top tem p eratu re is considered as the uncorrected boiling point of the la s t portion of th e m aterial in one fraction, an d of the first portion of th e suc­

ceeding fraction. D istillation is continued until th e corrected boiling point exceeds 320° F.. or u n til the still pot is em pty. Af­

te r th e distillation is stopped, th e still pot is cooled, th e column is allowed to drain, the residue is rem oved and its volume m eas­

ured. Each distillation yields from 200 to 400 fractions, each rep­

resenting approxim ately 0.25% by volum e of the original charge.

T h e volume, th e specific g rav ity , and the refractive index for the m ercury g line an d th e sodium D line are determined for each fraction.

D E T E R M IN A T IO N O F A R O M A T IC S A N D N A P H T H E N E S

R efractive indices an d densities of m ixtures of arom atics with n aphthenes, w ith paraffins, or w ith m ixtures of naphthenes and paraffins are not ad d itiv e either on a volum e per cent basis or a

weight per cent basis, b u t th eir ad d itiv ity is m ore nearly linear using volum e per cent as shown in T able I I . F o r m ixtures of aro­

matics, naphthenes, and paraffins th e specific dispersions likewise are not additive, b u t are m ore nearly so using a w eight p er cent basis as shown by Figure 1. F o r th is reason th e determ ination of arom atics by the use of specific dispersions is m ade on a w eight per cent basis and th is w eight per cent is th en converted to vol­

ume per cent.

. T he equation for weight per cent arom atics in a fraction is S / — S np

W = 100 + C (3)

where W is w eight per cent arom atics, S / is th e specific dispersion of th e fraction, S a is specific dispersion of th e individual arom atic

Table II. N o n a d d itiv ity of D en sity and Refractive In dex for M ix - tures of Toluene with n -H e p ta n e and with M e th y lc y c lo h e x a n e

D e v iatio n s of E x p e rim e n ta l D en sities a n d R efra ctiv e In d ices fro m T h e o re tic a l

(T h eo retica l-E x p e rim e n ta l X IQ4) C om position of B lends in

T erm s of N o n aro m atic

C o m p o n en t W eig h t %

W eight % n -h ep tan e

V olum e %®

n -h e p ta n e „ B a s i s d l ° ^{„3 0}n D

100.00 100.00 0 0

9 8 .9 8 9 9 .1 9 5 3

9 6 .9 8 9 7 .6 0 13 8

9 4 .9 7 9 5 .9 8 20 13

8 9 .9 7 9 1 .8 9 38 25

7 9 .9 8 8 3 .5 0 69 45

7 0 .1 7 7 4 .8 5 92 61

5 0 .3 0 5 6 .1 5 113 76

2 9 .9 8 3 5 .1 3 100 69

19.99 2 4 .0 2 77 54

10.02 12.35 43 32

5 .0 2 6 .2 7 23 17

3 .0 3 3 .8 0 13 11

1.01 1 .2 7 4 4

0 .0 0 0 .0 0 0 0

M eth y lcy clo h ex an e

10 0 .0 0 100 .0 0 0 0

9 8 .8 7 9 9 .0 0 5 2

9 4 .8 7 95 .4 1 12 9

89 .9 1 9 0 .9 3 23 15

6 9.9 1 7 2 .3 2 53 35

4 9 .9 4 5 2 .8 7 56 41

3 0 .0 4 3 2 .5 6 46 36

10.03 1 1 .1 5 21 16

5 .0 3 5 .6 2 10 9

1 .0 6 1 .1 9 3 2

0 .0 0 0 .0 0 0 0

V olum e % .„„B asis „

03 7 13 24 27 23 10 4 1

0

0 1

1

2 5 7 10 13 13 10 7 4 3I 0 01

5 7 2017 18 8 4 1 0

a C alcu la te d fro m w eig h t a n d d e n s ity of co m p o n en ts